Patent GB-1016253-A (GB)
Title: Improvements in or relating to manually operable crimping tools
Inventor: WALTON WILLIAM
IPC: H01R43/042
Filed: 1961-06-02
Abstract: 1,016,253. Jointing by stamping. PLESSEY CO. Ltd. May 23, 1962 [June 2, 1961], No. 19986/61. Heading B3Q. In a manually operable crimping tool the movement of the crimping jaws during the crimping operation is arranged to be produced by the release of energy from an energy store such as a spring which is energized between crimping operations. The tool comprises a body 1 to which is attached a frame member 2 having a number of crimping jaws 3. A thrust pin 5 which actuates the jaws 3 is connected to a piston 6 slidable axially of the pin 5 in a bore 7 of a housing 8 integral with the body 1. A return spring 4 opens the jaws 3 after the crimping operation has been completed. A multi-disc spring 11 arranged on a rod 12 is positioned within the cylinder bore 7 which is closed at one end by the body 1 and at the other by a plug 10 having a passage 32. The remainder of the bore is filled with hydraulic fluid and the spaces on each side of the piston 6 are interconnected by bores 13, 14 and a bore 15 of a pump cylinder member 16 located in a housing 8, a non-return valve 17 co-operating with one end of the bore 15. A piston 18 slides in the bore 15 and is connected by link rods to a hand lever 20 pivoted at 21 in a pistol grip portion 22. A spring 23 biases the lever 20 to move it out of the grip 22 thereby moving the piston 18 away from the valve 17. When the lever is pressed in the piston 18 forces fluid from the space between the piston 6 and plug 10 into the space between the piston 6 and body 1 thereby causing the piston 6 to compress the spring 11. Repeated operations of the lever increases the load on the spring 11 whilst the valve 17 prevents return flow of the fluid. The parts to be crimped are inserted between the jaws 3 and the fluid released by moving the lever 20 into the handle 22 beyond its normal travel so that the pumping stroke causes the end of the piston 18 to strike the non-return valve 17 and lift it from its seat. The stroke of the lever 20 is limited by an adjustable stoppin 24 which contacts the raised portion of a rotatable cam 26, the cam is rotated prior to the crimping stroke by a latch to allow the lever to over-travel and the stop-pin 24 to abut the low portion of the cam thus allowing the piston to release the valve 17. A pair of dogs 30 attached to the cam 26 engage a groove on the pin 24 to hold the lever in its loaded condition. In a modification, Fig. 5 (not shown), the non- return valve 17 and the pump assembly are retained coaxially within a spring guide-rod 42 on which the piston 6 is slidably mounted. A ram piston 48 having a head portion 54 which is spring 43 loaded is actuated by a lever 50 through a roller 49 which is carried by an arm 55 pivoted on the same pin 57 as the lever 50 and having an adjustable set-pin 56 co-operating with a pad 57 of the lever. The degree of travel of the lever 50 is controlled by a headed locking pin 58 which engages a spring-loaded rotary locking ring 60, 61 having apertures 62, 64 which limit the lever movement to any one of three positions as in the previous example, i.e. pumping, pressure release and hold.